Intraoperative optical coherence tomography-guided deep anterior lamellar keratoplasty

Gauging stromal dissection depth is crucial to successfully perform deep anterior lamellar keratoplasty (DALK) surgery. Intraoperative optical coherence tomography (iOCT) offers a promising tool to aid DALK surgery but visualization of surgical maneuvers is impaired due to artifacts from metallic instruments. We describe a novel surgical technique utilizing suture-assisted iOCT guidance that facilitates clear visualization of corneal dissection planes during DALK. A stromal dissection tunnel is performed with a Fogla probe and its depth is subsequently identified by threading a 1 cm segment of 8-0 nylon into the tunnel. In contrast to the Fogla probe, the 8-0 nylon is conspicuously highlighted on iOCT. If the tunnel is too superficial, a separate, deeper stromal tunnel can be created and visualized again with the 8-0 nylon suture and iOCT. This iterative process facilitates a deep stromal dissection, increasing the probability of successful big-bubble formation and Descemet baring DALK surgery. This technique was utilized for a successful big-bubble DALK in a patient with severe keratoconus.